A typical powder coating material application system includes one or more sources or supplies of powder coating material, a pump arrangement and a spray applicator such as a spray gun. Usually the powder coating materials are sprayed within a spray booth that contains powder overspray and also has an overspray recovery system to collect powder overspray and either reclaim it for further use or disposal. Spray guns are typically either manual guns that are hand held during operation, or automatic guns that are mounted on a support and are triggered and controlled by an electronic control system. The spray guns may be electrostatic such as corona or tribo-charging, or non-electrostatic. A supply hose is commonly used to connect a powder source such as a hopper to a pump inlet, and a feed hose is commonly used to connect a pump outlet to a spray gun inlet or multiple gun inlets. These hoses are typically flexible plastic hoses.
Many powder coating material application systems are designed to apply a wide variety of powder coating materials to an even wider variety of objects. Different powder coating materials usually involve different colors, but may further include different types of material such as polymeric, such as for example epoxies, polyesters and hybrids of epoxies and polyesters, or metallic, for example polyester with aluminum flake. In order to change over from spraying one type or color powder coating material to another, the application system must be thoroughly cleaned of the previous material before the next material is sprayed, in order to prevent contaminating the new spraying operation. This involves not only cleaning exterior surfaces such as the spray booth and spray guns, but also the entire powder flow path from the supply to the pump and through the outlet of all of the spray guns that were used in the previous spraying operation. These color change or material change operations are time and labor intensive and therefore are a significant cost factor.